Fluid drive and retarding means for kerf cutting machines



2 Sheets-Sheet June 12, 1956 F. A. LINDGREN FLUID DRIVE AND RETARDING MEANS FOR KERF CUTTING MACHINES Filed Oct. 17, 1952 Nu Ha O iii WEE:

vii/4 a fit/Enter? r June 12, 1956 LINDGREN 2,750,153

FLUID DRIVE AND RETARDING MEANS FOR KERF CUTTING MACHINES Filed Oct. 17, 1952 2 Sheets-Sheet 2 VAR/ABLE PRESSURE RELIEF VALVE 95 II 1 may!!! Jim/E227 Z'Er' United States Patent FLUID DRIVE AND RETARDING MEANS FOR KERF CUTTING MACHINES Frank A. Lindgren, Chicago, Ill., assignor to Goodman Manufacturing Company, Chicago, Ill., a corporation of Illinois Application October 17, 1952, Serial No. 315,330

2 Claims. (Cl. 254-184) This invention relates to improvements in kerf cutting machines of the room and pillar type and more particularly relates to the fluid drive and retarding means for such machines.

A principal object of my invention is to provide a novel and improved form of fluid drive and retarding means for a kerf cutting machine of the room and pillar type arranged with a view toward simplicity and efficiency in operation and control.

Another object of my invention is to provide a kerf cutting machine of the room andpillar type having power driven head end tail rope drums with individual fluid motors for driving each drum, and having a variable pressure relief valve in the drive to the tail rope drum, operable to set-up a back pressure on the tail rope drum drive motor, and vary the resistance to rotation of said motor as a pump, upon a retarding pull" thereon by the tail rope.

Still another object of my invention is to provide asimple and improved kerf cutting machine of the room and pillar type having head and tail rope drums for propelling the machine along the ground and controlling. the position thereof during the cutting operation with individual fluid pressure circuits and motors for driving each drum, and with a variable pressure relief valve in the drive to the tail rope drum, adjustable to set up a back pressure against rotation of the tail rope drive motor as a pump and afford a resistance to unwinding of the tail rope drum, to retard angular movement of the rear end portion of the machine.

Another and more detailed object of my invention is to provide a simple form of kerf cutting machine of the room and pillar type wherein the head and tail rope drums are individually driven through individual pumps and motors for each drum and wherein the pump affording a source of supply of fluid under pressure to the tail rope drum also affords a source of supply of fluid under pressure to certain other operative parts of the machine, and the pump affording a source of supply of fluid under pressure to the head rope drum is directly connected thereto through the control valve therefor to avoid interruption in the drive to the head rope drum during the operation of various other operative parts of the machine.

Still another object of my invention is toprovide a novel and improved form of retarding device for the tail rope drum of a kerf cutting machine driven from a fluid motor and controlled by a flow control valve, and having a variable pressure relief valve connected between the flow control valve and the fluid motor, to set up a backpressure on the fluid motor when driven at times as a pump by the tail rope drum, to vary the resistance afforded to unwinding of the tail rope drum.

These and other objects of my invention will appear from time to time as the following specification proceeds and with reference to the accompanying drawings wherein:

Figure 1 is a plan view of a kerf cutting machine con 2,750,153 Patented June 12, 1956 ice structed in accordance with my invention with certain parts broken away and certain other parts shown in horizontal section;

Figure 2 is a diagrammatic view schematically showing the fluid diagram for the various operative parts of the machine; and

Figure 3 is a vertical sectional view taken through the variable pressure relief valve utilized to control the retarding of the tail rope drum of the machine.

In the embodiment of my invention illustrated in the drawings, I have shown a kerf cutting machine 10 of the room and pillar-type which may be slidable along the mine bottom on its own bottom during the cutting operation as is usual with kerf cutting machines of the class described.

The kerf cutting machine 10 is shown as including a main frame 11 secured to and extending forwardly from a motor 12 and having a cutter bar 13 projecting forwardly from its forward end. A cutter bit carrying cutter chain 14 orbitally driven by the motor 12 is shown as being guided for movement about the cutter bar 13.

A head rope drum 15 having a flexible draft device 16 thereon and a tail rope drum 17 having a flexible draft device 18 thereon are provided on opposite sides of the main frame 11 to feed and control movement of the machine along mine bottom on its own bottom in a well known manner, it being understood that during cutting across a coal face from right to left that the tail rope drum 17 and draft device 18 serve to retard movement of the rear end of the machine ahead of the forward end of the main frame 11 adjacent the coal face and to maintain the machine frame and cutter bar 13 generally perpendicular to the coal face.

The motor 12 is provided with a motor pinion 19, which may drive an intermediate shaft (not shown), which intermediate shaft may serve to drive the cutter chain 14 about the cutter bar 13 in a usual manner, and no part of my present invention so not herein shown or described. The motor 12 also serves to drive two aligned and connected fluid pumps 20 and 21, shown as being directly connected with the shaft of said motor through a coupling 22. The pump 21 is shown in Figure 2 asbeing connected to supply fluid under pressure to .a fluid motor 23 which serves to drive the head rope drum 15. The pump 20 is shown as having fluid connection with the manifold of a valve bank 24, for supplying fluid under pressure to two front elevating and tilting jacks 25, 25 and two laterally spaced rear tilting jacks 26, 26. Where the machine may be supported on continuous traction tread devices as in my application Serial No. 300,621, filed July 24, 1952, and entitled Self-Propelled Room and Pillar Kerf Cutting Machine, the jacks 25, 25 may tilt the machine about the axes of the drive sprockets for the tread devices (not shown) and elevate the cutter bar and machine above the ground for transportation. The rear tilting jacks 26, 26 may be beneath the control and resistance compartments for the motor 12 and may be connected with a transverse tilting shoe (not shown) for tilting the rear end of the machine about the forward end portion thereof as in my aforementioned application Serial No. 300,621. The jacks 25, 25 may also be used to tilt the machine in cooperation with jacks 26, 26 about an axis extending longitudinally of the machine.

The pump 20 also affords a source of supply of fluid under pressure to drive a fluid motor 27 for driving the tail rope or retarding drum 17, fluid under pressure being supplied to said motor 27 from the pump 21 through the manifold for the valve bank 24.

The motor 23 being entirely independent of the source of supply of fluid under pressure to the motor 27 and the jacks 25, 25 and 26, 26 may thus be operated during operation of either or both of the jacks 25, 25, or 26, 26

3 and the tail rope drum drive motor 27 without interruption or retarding of the feeding of the machine across the coal face during the kerf cutting operation.

The motors 23 and 27 may each be of a similar construction and may be well known forms of sliding vane or gear types of hydraulic motors having suflicient torque capacity to efliciently drive the respective drums at the required speeds to feed the machine across the coal face to efliciently cut a kerf therein. The tail rope drum drive motor should also be capable of operating as a pump in cases where the tail rope may be payed off the tail rope drum faster than it is driven by its motor, and may in this manner drive the tail rope drum and its drive motor as a pump.

The motor 23 is shown in Figure 1 as driving the tail rope drum through a suitable gear reduction train 29 including a motor pinion 30, an idler pinion 31 driven thereby, a spur gear 33 driven by said idler pinion and keyed or otherwise secured to a transverse shaft 34. The gear train also includes a pinion 35 on the transverse shaft 34, meshing with and driving a spur gear 36 on a parallel transverse shaft 37. The transverse shaft 37 is shown as having a pinion 39 thereon, meshing with and driving an internal gear 40. The internal gear 40 is shown as being keyed or otherwise secured to a transverse shaft 41 for driving the same. The transverse shaft 41 is shown as having a pinion 43 on its outer end which meshes with and drives an internal gear 44. The internal gear 44 is secured to the head rope drum 15 and drives the same about a stud shaft 45, on which it is rotatably journaled. The shafts 34, 37 and 41 may be suitably supported and journaled in the main frame 11, in any well known manner which need not herein be shown or described since it forms no part of my present invention.

The drive from the motor 27 to the tail rope drum 17 is through a reduction gear train generally indicated by reference character 47, like the reduction gear train 29 so need not herein be described in detail.

As shown in Figure l of the drawings, the main frame 11 forms a housing and bearing support means for the gearing for driving the cutter chain 14 about the cutter bar 13 and for driving the head and tail rope drums 15 and 17. The main frame 11 also may be sealed to form a fluid storage tank and a source of supply of fluid for the pumps and 21. The top of the main frame 11 is shown as being covered by a removable cover 49 suitably sealed thereto as by a gasket (not shown) and detachably connected thereto as by studs and nuts or cap screws 50, 50.

Referring now to Figure 2 of the drawings and the fluid pressure system for driving the motors 23 and 27 and operating the elevating and tilting jacks 25, and 26, 26, the fluid pump 21 is shown as having an intake 51 for taking hydraulic fluid directly from the interior of the main frame 11 within which said pump is encased. The interior of the main frame 11 will hereinafter be referred to as the tank. The pressure side of the pump 21 is shown as being connected with a flow control valve 53 through a pressure line 54. An intake line 55 having a check valve 56 therein connects the pressure line 54 with the tank, to afford a source of supply of fluid, in cases where the direction of rotation of the motor 12 may be reversed during the tramming operation of the machine, or when freeing the cutter bar from the coal seam in cases where it may become jammed in the seam, so as to bypass the flow control valve 53. The flow control valve. 53 is shown as being connected with a safety relief valve 57 through a pressure line 59. The safety relief valve 57 is shown as being connected with a fluid motor 23 for supplying fluid under pressure thereto to drive the same, through a pressure line 60. The discharge from the motor 23 is through a discharge line 61 discharging to tank.

The flow control valve 53 may be a well known form of flow control valve of the pressure compensated type such as the series F-206 pressure compensated flow control valve manufactured by Vickers, Inc., of Detroit, Michigan. The flow control valve 53 is provided to adjust the flow range to supply varying volumes of fluid under pressure to the motor 23 for driving the same at varying speeds, and variations in pressure are compensated for, to insure a uniform flow of fluid at any setting of the valve regardless of pressure variations. As herein shown, the output flow volume of the valve is adjusted by the operation of a control handle 63 located at the rear of the motor 12 and connected with the valve 53 by means of operating rod 64. Operation of the control handle 63 may thus vary the delivery volume of the valve from a low delivery volume to the volumetric capacity of the motor 21, and thus supply fluid to the motor 23, to rotatably drive the feed drum 15 at the required speed. The flow control valve 53 may also be provided with a pressure release valve 62, to relieve pressure therefrom and from the line 54 upon overload conditions and to by-pass pressure back to the tank when the valve is closed and the pump 20 is in operation.

The pump 20 is shown as having an intake 65 leading from the tank, and as having a pressure line 66 connected to the valve bank 24. An intake 69 having a check valve 70 connected therein is connected in the pressure line 66 to take care of conditions where the motor 12 may be reversed. The valve bank 24 is shown as having a plurality of valves 71, 71 and 72, 72 connected therein to control the supply and release of fluid under pressure to the jacks 25, 25 and 26, 26. The valves 71, 71 and 72, 72 may be operated by operating handles 73, 73 and 74, 74, respectively, at the rear of the motor 12 and may be any suitable commercial form of valve, preferably of the piston or spool type, and are no part of my invention so need not herein be described further.

The pressure line 66 is connected through the manifold of the valve bank 24 with a pressure line 74 leading to a flow control valve 75, like the flow control valve 53. The flow control valve 75 is shown as being operated by a control lever 76 at the rear end of the machine to open or close said valve and control the volume of fluid under pressure supplied to the fluid motor 27 and thus to vary the speed thereof. The flow control valve 75 is like the valve 53 and may be a pressure compensated control valve of the series F206 type manufactured by Vickers, Inc, of Detroit, Michigan, and is also provided with a pressure relief valve 77 therein to by-pass pressure back to the tank upon overload conditions, as when the valve 75 may be shut off. 1

A pressure line 79 having a check valve 80 therein to prevent the back flow of pressure into the valve 75 when the motor 27 is driven as a pump connects the valve 75 to a variable pressure relief valve 81. A pressure line 83 connects the relief valve 81 with the intake of the fluid motor 27 to supply fluid under pressure thereto and operate the same. A return line 84 leads from the discharge of the fluid motor 27 to tank, to return fluid thereto. The fluid motor 27 is connected with the tail rope drum 17 by the gear train 47 as previously described.

The variable pressure relief valve 81 diagrammatically illustrated in cross-section in Figure 3 may be a well known form of balanced piston type of relief valve, such as the type CD-06B valve manufactured by Vickers, Inc., of Detroit, Michigan. The intake line 79 may be connected with an intake passageway 85 of the valve and the pressure line 83 may be connected with a pressure passageway 86 thereof. Fluid is shown as being relieved from the pressure passageway 85 by means of a valve 87 normally blocking the passage of fluid through a discharge passage way 88 and opening upon overload conditions to discharge fluid through the passageway 88. The discharge passageway 88 is shown as leading directly to tank.

As herein shown the relief valve 81 is provided with a piston 89 having a balancing passageway 90 leading therethrough to a piston chamber 91. The valve 87 is shown as being biased to a closed position by a spring 92 seated in the piston chamber and engaging the balancing side of the piston 89 and a second spring 93 seated in a guide stem 94 for the reEfef valve. The pressure of fluid in the piston chamber 91, plus the force exerted by the springs 92 and 93 thus biases the valve 87 into a closed position, to maintain the free flow of fluid therethrough until overload conditions occur.

The relief of pressure from the piston chamber 91 and the balancing side of the piston 89, to open the valve 87 upon overload is controlled through a relief passageway 95 leading to a relief valve 96 engaging a seat 97, and opening to relieve fluid pressure through a passageway 98 leading through the valve 87 to the discharge passage 88. The relief valve 96 is shown as being engaged with its seat by a spring 99 seated on the inner end of a pressure varying screw 100, threaded within a nut 101 threaded in the end of the valve casing. The pressure varying screw 100 is shown as being operated to vary the loading of the spring 99 from the rear end of the machine by an operating handle 105 connected with said valve through a rod 106 and coupling 107.

When the pressure on the pressure side of the piston 89 becomes excessive, fluid passing through the passageway 95 and seat 97 will unseat the valve 96. This will relieve pressure from the piston chamber 92 and the balancing side of the piston 89 through the passageway 98 leading through the interior of said piston. When this occurs the piston 89 will move along its chamber against the springs 92 and 93 and discharge fluid directly to tank, until the pressure in the pressure line 83 is reduced to an extent sufficient to accommodate the valve 96 to close, at which time the pressure on the balancing side or the piston 89, plus the force exerted by the springs 92 and 93 will move the piston 39 downwardly to close the valve 87.

Since the check valve 80 is in the pressure line 79, the valve 81 serves only to relieve pressure from the pressure line 83. When the motor 27 is driven as a pump, a back pressure is put in said pressure line which is added to the pressure supplied by the pump 20.

When the machine is normally cutting across a coal face, the head and tail rope drums and 17 may be driven in the same direction by their respective motors 23 and 2'7. The cables 16 and 18, however, may be wound on their respective drums in opposite directions. The head rope 16 may thus be wound on the head rope drum 15 to pull the machine across the coal face in the usual manner, while the tail rope 18 may be unwound from its respective drum at substantially the same rate of speed as a head rope is wound on it's drum, to maintain the cutter bar and machine frame generally perpendicular to the coal face while cutting thereacross.

When, however, conditions arise in which the reaction on the cutter bar tends to hold the cutter bar from advancing with the machine frame, the tendency will be for the rear end of the machine to move ahead of the cutter bar. The machine frame and cutter bar if not retarded would thus move to an inclined position with respect to the coal face and the tendency will be for the cutter bar to move out of the kerf. When such conditions occur, cable is wound from the tail rope drum 17 faster than it is payed off of said drum. This will cause the rope 18 to drive said drum. Driving of the drum 17 by the rope 18 will then rotatably drive the motor 27 through the gear train 47 as a pump against the pressure of the fluid in the pressure passage 83 supplied by the pump 20.

The motor 27 acting as a pump will then take pressure from tank through the discharge outlet 84 and will pump fluid pressure back into the line 83 and valve 81 against the pressure coming into said line and valve from the valve 75. A fluid block in the pressure line 83 may then occur until relieved by operation of the relief valve 81. This will hold the tail rope drum 17 from rotation and the pull of the head rope and the forward end of the machine against the retarding, action of the tail rope will pivot the machine frame and cutter bar to again extend in the desired position with respect to the coal face. During cutting across the face, the retarding action of the motor 27 and the tail rope drum 17 may be continually varied by operation of the hand lever 105, varying the pressures at which the relief valve 81 will open and dump fluid back to tank and the blocking eflect to rotation of the motor 27 as a pump.

It may thus be seen that the machine frame and cutter bar may be maintained generally perpendicular to the coal face during cutting thereacross, merely by operation of the hand wheel and varying the pressure at which the valve 81 will open and thus varying the blocking to rotation of the motor 27 as a pump, as desired.

It will be understood that modifications and variations of the present invention may be effected without departing from the scope of the novel concepts thereof.

I claim as my invention:

1. A drive and retarding means for the purpose described comprising a pump, means for driving said pump, a fluid motor, a pressure line connecting said motor to said pump and a variable flow control valve in said pressure line, means for operating said valve to vary the flow to said motor and the speed thereof, a winding drum, 2. geared drive connection from said motor to said winding drum for driving said drum in an unwinding direction under the control of said valve, a check valve in said pressure line on the downstream side of said flow control valve and blocking the back flow of fluid to said valve, a pressure relief valve on the downstream side of said check valve, said winding drum being driven at times and driving said motor as a pump, and manually operable means for varying the pressures at which said valve relieves back pressure from said motor when driven as a pump and varying the resistance to said motor as a pump and the retarding effect of said winding drum.

2. In a fluid operated drive and retarding device particularly adapted for a kerf cutting machine having a head rope drum on the advance side of the machine and a tail rope drum at the opposite side of the machine, means for simultaneously driving said head and tail rope drums comprising an individual fluid motor for each drum, a separate pressure line leading to each fluid motor and a variable delivery volume flow control valve in each pressure line manually controllable to vary the delivery volume of fluid to an associated fluid motor and vary the speed thereof, the tail rope drum driving its fluid motor as a pump at times during the application of fluid under pressure to the drive motor therefor, a relief valve in the pressure line to said tail rope drum on the downstream side of the flow control valve therefor, a check valve between said flow control valve and relief valve blocking the passage of fluid from said relief valve to said flow control valve, and manually operable control means connected with said relief valve for varying the pressure at which said relief valve will relieve pressure from the tail rope drum drive motor and varying the back pressure 011 said tail rope drum drive motor when driven as a pump by said tail rope drum to vary the retarding effect of said tail rope drum.

References Cited in the file of this patent UNITED STATES PATENTS 1,639,255 Brackett Aug. 16, 1927 2,339,523 Sloane Jan. 18, 1944 2,395,302 Slomer Feb. 19, 1946 2,452,760 Jeffrey Nov. 2, 1948 2,530,720 Paulson Nov. 21, 1950 

